Can you drink so much water when running that it can harm you or even cause death? YES

The following has been extracted from Dr. Mercola website

Beverage Industry Hurt Athletes With Manipulated Science:

This isn’t the first time Dr. Tim Noakes has taken on big industry. In 2010, he published “Waterlogged: The Serious Problem of Overhydration in Endurance Sports,” a book exposing how industry influences science, and how the beverage industry has influenced the drinking guidelines for athletes.

He wrote the book because he was angry about people being hurt as a result of these manipulated guidelines. While rarely discussed, exercise-associated hyponatremia — drinking too much or overhydrating — actually contributes to many unnecessary deaths. Noakes explains:

“When I started running marathons in the 1970s, we didn’t drink during races. In fact, I ran a 56-mile race and I think I had four drinks. You’d have a drink every hour and you would literally swirl your mouth out with water and that would be about it. No one came to any harm. Then in about 1974 I began actively to promote drinking during marathon races. I became very active in South Africa saying there was not enough fluid available to marathon runners …

By 1981, the race … had a drinking station every mile. They had 56 drinking stations in a 56-mile race. At the end of that race, a lady was unconscious. She was hospitalized … Her blood sodium concentration had fallen. She wanted to know what had happened. She said, ‘Maybe I took too little sugar or salt during the race. What should I do about it?’ I said, ‘I have no idea.’

I then decided to investigate. Over the next 10 years, we were able to show that … she had overdrunk fluids. She’d retained the fluids, [which] caused her brain to swell, [causing] her to go unconscious. She’d remained unconscious for four days. We provided definitive evidence that it was overdrinking that caused the problem.”

In 1993, the first American marathon runner died from overhydration. Still, in 1996, the American College of Sports Medicine, funded by Gatorade, produced new drinking guidelines stating that dehydration is the killer when you exercise, and you should drink “as much as tolerable” during exercise.

Other deaths followed, all of which were completely unnecessary. In 2002, a young female runner died shortly after completing the Boston marathon. Cause of death: water intoxication. As recently as last year, two American football players died from overhydration. An estimated 3,000 athletes have also been hospitalized for hyponatremia, but fortunately almost all have survived. Yet, there have been at least 16 completely unnecessary deaths of which we are aware.

How Industry Controls Information.

Finally, in 2007, the American College of Sports Medicine revised their guidelines to what Noakes had suggested, which is that you should drink to thirst.

“It took a lot of time to change. The only reason we could change was because two scientific journals in the entire world were independent of the sports drink industry. [The] industry … makes sure its key opinion leaders, who have funds to do research, also happen to be the people who draw up the guidelines, whether they be dietary, cholesterol or drinking. In addition to that they are the main reviewers of journal articles.

Over a 10-year period, we would submit papers and I knew they went to exactly the same reviewers every time. It didn’t matter which journal we sent them to … But there were two journals that were independent, the British Journal of Medicine and the Clinical Journal of Sports Medicine. They published our work. I always knew that if there were two journals open to our papers … we would win in the end. In the end, we did win, because in the end all that matters is the truth.

But if those two journals had also been controlled, if they’d had the same editorial boards, we wouldn’t have ever done it. That was how I learned that is how industry controls information. They actively do it. They actively support people to make sure that only guidelines that benefit industry are ever published.”